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1.
可穿戴电化学传感器件是一种可直接穿戴在身体特定部位、甚至植入用户体内的柔性电化学传感器。其具有简易性、便携性、灵活性等特点,可实时电化学监测与跟踪分析待测物,被广泛用于医疗保健、人体健康和环境监测等领域。该综述概括了可穿戴电化学传感器件的硬件设计与研制,及其在汗液检测、神经化学监测、现场分析检测(POCT)中的应用,总结和展望了可穿戴电化学传感器件的未来发展趋势,以期为可穿戴电化学传感领域的进一步发展提供参考。  相似文献   

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3.
    
The development of new tools with outstanding performance for monitoring neurotransmitters is a challenging task in neuroscience. Electrochemical probes have attracted tremendous attention for the identification and quantification of neurotransmitters, owing to their demonstrated potential for quick response, real-time measurements, elevated selectivity and sensitivity. In this Review, we have focused on the recent developments of carbon nanotube (CNT)-based electrochemical sensors for dopamine detection. The use of CNTs is beneficial for this task, because of their high tensile strength, flexibility, good electrical conductivity, and low thermal expansion coefficient. Therefore, electrochemical sensing approaches with CNTs have opened the door for researchers working towards neurobiomedical applications.  相似文献   

4.
    
The chemical stability and electrocatalytic properties of boron-doped diamond (BDD) electrodes give rise to various applications. While wastewater treatment is the most widely studied field, the use of BDD for soil remediation and environmental sensing is currently investigated more and more. With regards to soil remediation, promising results have been reported for the treatment of soil washing solutions. Anodic oxidation using BDD at high current density allows high mineralization rates of biorefractory soil pollutants and extracting agents to be reached. At low current density, selective degradation of target pollutants has been achieved, thus allowing the reuse of extracting agents for further soil washing steps. BDD-based electrochemical sensors have been studied for chemical oxygen demand determination, pesticide/pharmaceutical detection as well as other applications such as pH, O2 and analysis of various organic and inorganic compounds. Low detection limits, wide linear ranges and low standard deviations have been achieved. The main reasons behind the superiority of BDD sensors are the chemical stability, wide applicability and resistance of BDD towards biofouling. The beauty of BDD sensing is that it can work for a variety of organic and inorganic compounds under many physicochemical parameters.  相似文献   

5.
张强  姚章权  周蓉  杜玉扣  杨平 《化学学报》2012,70(20):2149-2154
利用化学-电化学方法制备了Ag/Au/Pt复合催化剂. 该催化剂以100 nm左右的Ag颗粒为基底, 以化学方法沉积金再电沉积铂, 这降低了贵金属Au和Pt的用量. 通过SEM, EDX和XRD对样品进行表征, 并测试对甲酸的电催化氧化性能. 研究表明, 当Pt∶Au原子数比小于1∶10时, 主要表现为直接氧化, 在较低的Pt负载量(0.71 μg/cm2)情况下, Ag/Au/Pt复合催化剂对甲酸氧化的直接氧化峰电流密度达到最大. 甲酸的电催化氧化稳定性实验表明, 当Pt载量为0.05 μg时, 相对于最大峰电流密度, 循环伏安扫描第100圈时甲酸氧化的直接氧化峰电流密度仅衰减了2.29%. 同时CO氧化剥离实验表明, 当Pt∶Au=1∶6时, Ag/Au/Pt复合催化剂对CO氧化峰电势最负, 相对于纯Pt催化剂负移了大约0.13 V, 表明该复合催化剂具有更好的抗CO毒化能力.  相似文献   

6.
方莉  贺进禄 《化学进展》2015,27(5):585-593
葡萄糖传感器在几十年的发展中取得了重大进展,经历了三代基于酶葡萄糖传感器之后,现已进入第四代无酶葡萄糖传感器的发展阶段.本文从基于酶和无酶两类介绍了不同葡萄糖传感器的测试原理,综述了近年来纳米材料在无酶电化学葡萄糖传感器方面应用的主要研究进展,对不同类别纳米材料的制备方法以及所构建传感器的灵敏度、选择性、检测范围和稳定性等进行了评述,分析了制约无酶葡萄糖传感器商业化应用的主要原因.其中,贵金属纳米材料主要讨论了铂、金和钯;过渡金属纳米材料主要讨论了镍、铜以及其氧化物;双金属纳米材料主要讨论了合金和复合物;碳纳米材料主要讨论了单壁(多壁)碳纳米管和石墨烯.此外,本文也对无酶葡萄糖传感器的发展方向和趋势进行了展望.  相似文献   

7.
    
A three‐sensor array consisting of a graphite‐epoxy composite electrode (GEC), 4‐carboxybenzo‐18‐crown‐6‐GEC and 4‐carboxybenzo‐15‐crown‐5‐GEC was employed for the simultaneous determination of Cd(II), Pb(II) and Hg(II) by differential pulse anodic stripping voltammetry (DPASV). Sensors were firstly studied for the determination of Hg(II); secondly, peak current responses confirmed that all sensors showed differentiated response for the three considered metals. A response model was developed to resolve mixtures of Cd(II), Pb(II) and Hg(II) at the µg L?1 level; Discrete Wavelet Transform was selected as preprocessing tool and artificial neural network used for the modelling of the obtained responses.  相似文献   

8.
《Analytical letters》2012,45(14):2281-2300
Abstract

The analytical approaches for the determination of trace concentrations of heavy metals in aquatic systems are briefly introduced. A detailed review on the recent advances of microelectrodes is presented, including the definitions, types, advantages, theory, and fabrication of microelectrodes. The application of microelectrodes on the measurements of trace metals in water is focused on the voltammetric‐, potentiometric‐, and in situ electrochemical sensors.  相似文献   

9.
C-H键是有机化合物中最基本的化学键,C-H键的活化和直接转化避免了反应物的预先官能化,是最终实现烷烃类化合物转化为不同种类有机化合物最直接、高效的转换方式,通过C-H键构建C-X键(X=O、C、N)是非常重要和具有挑战性的研究. C-H键直接电氧化活化过程中以“电子”参与反应,不需要加入额外的催化剂,并可通过选择合适的电极材料、支持电解质、溶剂和反应温度,通过恒电流或者恒电位电解,进行具有特定的反应选择性和区域选择性的C-H键电氧化活化,从而获得含其他活性基团的目标产物.  相似文献   

10.
    
A simple and efficient procedure is described for the electrochemical determination of ledipasvir (LDP) in presence of co‐formulated drug sofosbuvir (SOF). Herein, a highly sensitive, low‐cost electrochemical protocol was utilized to fabricate a zeolite modified carbon paste electrode (ZY/CPE) through mixing of zeolite nanostructures with graphite powder. The fabricated sensor displayed high sensitivity, allowing optimal charge transfer/electrode kinetics. Different experimental and chemical factors, including electrode composition, effect of pH, scan rate and amount of ZY were evaluated carefully to obtain the highest electrochemical response. Under optimized conditions and using square wave voltammetry (SWV), the current response of the ZY/CPE electrochemical sensing platform exhibited a detection limit of 7.5×10?9 M and a large linear range from 5.0×10?8 to 1.0×10?4 M. The practical applicability of the suggested electrochemical platform was verified in the assessment of LDP in pharmaceutical formulations with excellent recoveries in the range of 99.50–98.87 %. Moreover, a biological relevance of the developed sensor was established by the analysis of LDP in human urine and plasma samples with satisfactory recoveries of 99.00 and 99.68 %, respectively. Due to the simplicity and ease of preparation of the proposed sensor, it can be used in quality control laboratories and for clinical analysis.  相似文献   

11.
    
Owing to their versatility and unique characteristics, graphene-based materials have been used extensively for the development of electrochemical sensors and biosensors. The key to the maximum potential of these materials is the understanding of the role their structure plays in their modification processes. Herein, we summarize some structural characteristics of graphene oxide (GO) and reduced graphene oxide (rGO) and explore different surface modification methods for electrochemical sensing applications. surveyed the most recent applications of these materials as (bio)sensors, particularly for environmental monitoring and health-related applications, such as quantification of biomarkers and metabolites and detection of cancer cells. The low detection limits, selectivity toward target molecules, and robustness of GO- and rGO-based electrodes render them critical materials for the preparation of sensors for routine analysis and monitoring.  相似文献   

12.
纳米钯催化剂对甲醇的电催化氧化   总被引:1,自引:0,他引:1       下载免费PDF全文
牛凤娟  易清风 《电化学》2011,17(1):67-72
采用水热法,以甲醛作还原剂还原Pd2+-EDTA络合物,制得钛基纳米钯颗粒电极(nanoPd/Ti).扫描电子显微镜(SEM)显示,纳米钯颗粒直径约为60 nm,形成三维立体网状结构.在碱性溶液中,循环伏安及交流阻抗测试分别表明:nanoPd/Ti电极对甲醇氧化有极高的阳极电流、较低的起始氧化电位和较强的抗CO毒化能力.在nanoPd/Ti电极上甲醇电氧化反应的阻抗值较低,增加甲醇浓度,电极阻抗更低.电极对甲醇氧化具有极好的电催化活性.  相似文献   

13.
The electrochemical oxidation of sulfide on a polycrystalline platinum electrode was studied under potentiostatic condition when an external resistor is in series with the working electrode. Only two os- cillatory regions can be obtained in the absence of the external resistance, but four oscillatory regions, including two new current oscillations, were found in this system by controlling the external resistance. It is demonstrated that three oscillatory regimes, which arise on the positive branch of current-potential curve, can be classified as HN-NDR (Hidden N-shaped Negative Differential Resistance) oscillators. For the first oscillatory region, various transient complex phenomena, which result from the change of the electrode/electrolyte interface by accumulation of adsorbed element sulfur on the electrode, have been observed. The dynamic behavior of NDR (Negative Differential Resistance) oscillations, appearing along with negative branch of polarization curve, can transform from oscillations into bistability with a sufficient large external resistance in series. Two oscillatory regions in high-potential region classified as HN-NDR type oscillations are separated by a saddle-loop bifurcation. They displayed a sequence of bursting oscillations and irregular oscillations, respectively. The electrochemical oxidation of sulfide provides a model system for studying complex dynamics and possible application in sulfur removal.  相似文献   

14.
The electrochemical properties of single crystals of cerium fluoride alloyed with bivalent cations Sr2+, Ca2+, Ba2+, Sr2+ + Ca2+, Sr2+ + Ba2+, Ba2+ + Ca2+ and also with La3+ and La3+ + Ba2+ cations are studied using the dynamic voltammetry and impedance spectroscopy. The conductivity of symmetrical cells with Ag electrodes is determined using the method of impedance spectroscopy in the frequency range from 450 to 5 kHz at the temperatures from 20 to 100°C: for CeF3: Sr2+ (0.5 mol %) + Ba2+ (0.5 mol %), σ = σ0 exp[(?0.284 ± 0.005/kT]; for CeF3:Ca2+ (0.5 mol %) + Sr2+ (0.5 mol %), σ = σ0 exp[(?0.292 ± 0.017/kT]. The steady-state and dynamic voltammogams of symmetrical electrochemical cells with nonpolarizable reference electrodes and CeF3 single crystals alloyed with Sr2+, Ca2+, and Ba2+ bivalent cations exhibited ohmic polarization. For cells with CeF3 containing La3+ as an admixture, a hysteresis was observed, which could not be eliminated by chemical and electrochemical treatment of crystals. In the dynamic voltammetric curves of asymmetric cells with nonpolarizable and silver electrode and CeF3 crystals alloyed with Sr2+, Ca2+, and Ba2+, a range of ideal polarizability (from 0 to ~?2.7 V), and also cerium redox processes and silver fluorination-boundary regeneration were observed. In the dynamic voltammetric curves of asymmetric cells with CeF3 containing La3+ admixture, no range of ideal polarizability was observed; however, the reactions of silver fluorination and reduction of solid-electrolyte cerium were well pronounced at the corresponding potentials.  相似文献   

15.
托美汀的吸附伏安法研究   总被引:2,自引:0,他引:2  
谭学才  李耀华 《分析化学》1998,26(4):439-442
在0.2mol/L NH3-NH4Cl底液中,托美汀在悬汞电极上有一灵敏的还原峰。峰电位为Epc=-1.48V,该峰具有明显的吸附性,峰电流ipc与TOL浓度在4.0×10^-9-7.0×10^-7mol/L范围内呈线性关系;检出限为5.0×10^-10mol/l,用该法测定了片剂TOL的含量,结果良好。  相似文献   

16.
曾泳淮  周颖林 《分析化学》1999,27(7):832-835
在NH_3-NH_4Cl底液中,尼莫地平(nimodipine,NMD)在汞电极上有一线性扫描还原峰,峰电位E_(pc)=-0.62V(vs.Ag/AgCl).该峰具有明显的吸附性,吸附粒子为NMD中性分子.测得NMD在汞电极上的饱和吸附量为1.49 ×10~(-10)mol/cm~2,每个NMD分子所占电极面积为1.11nm~2,NMD在悬汞电极上的吸附符合Frumkin等温式.测得吸附系数β=4.32×10~5,吸附因素γ=0.46;吸附自由能△G°=-32.14kJ/mol;电子转移数n=4;不可逆吸附的动力学参数αn_α为1.10.探讨了NMD在汞电极上的还原机理,并建立了吸附溶出伏安法测定NMD的最佳条件,检测限为1.0×10~(-9)mol/L.  相似文献   

17.
    
In the present work, the Pt(111) surface was disordered by controlling the density of {110}- and {100}-type defects. The cyclic voltammogram (CV) of a disordered surface in acid media consists of three contributions within the hydrogen adsorption/desorption region: one from the well-ordered Pt(111) symmetry and the other two transformed from the {111}-symmetry with contributions of {110}- and {100}-type surface defects. The ethanol oxidation reaction (EOR) was studied on these disordered surfaces. Electrochemical studies were performed in 0.1 M HClO4+0.1 M ethanol using cyclic voltammetry and chronoamperometry. Changes in current densities associated to the specific potentials at which each oxidation peak appears suggest that different surface domains of disordered platinum oxidize ethanol independently. Additionally, as the surface-defect density increases, the EOR is catalysed better. This tendency is directly observed from the CV parameters because the onset and peak potentials are shifted to less positive values and accompanied by increases in the oxidation-peak current on disordered surfaces. Similarly, the CO oxidation striping confirmed this same tendency. Chronoamperometric experiments showed two opposite behaviors at short oxidation times (0.1 s). The EOR was quickly catalyzed on the most disordered surface, Pt(111)-16, and was then rapidly deactivated. These results provide fundamental information on the EOR, which contributes to the atomic-level understanding of real catalysts.  相似文献   

18.
米非司酮的吸附伏安特性   总被引:1,自引:0,他引:1  
曾泳淮  张光润 《分析化学》1997,25(11):1278-1281
在PH7.0Britton-Robinson缓冲溶液中,米非司酮(Mifepristone,RU486)在汞电极上有2个不可逆的线性扫描还原峰,峰电位分别为-1.23V和-1.68V。本文探讨了第一峰的电化学行为。  相似文献   

19.
噻利洛尔的吸附伏安行为   总被引:1,自引:0,他引:1  
曾泳淮  李永明  陈小乐 《分析化学》1999,27(10):1136-1140
在NH3-NH4Cl底液中,噻利洛尔在汞电极上有一线性扫描还原峰,电位Epc=-1.31V(vs,Ag/AgCl),该峰具有明显的吸附性。当CEL浓度较小时,扫描较快,搅拌富集时间较长时,电极反应完全为吸附态的CEL的还原所控制,吸附粒子为CEL中性分子,测得CEL在汞电极上的饱和肿附量为1.03×10^-10mol/L,每个CEL分子所占电极面积为1.57nm^3,CEL在悬汞电极上的吸附符合L  相似文献   

20.
在0.1mol/LNH4Ac(pH7.8)底液中,氯氮平(CLP)在汞电极上有一线性扫描还原峰,Epc=-1.34V(vs.Ag/AgCl).该峰具有明显的吸附性,吸附粒子为CLP中性分子.测得CLP在汞电极上的饱和吸附量为2.7×10-10mol/cm2,每个CLP分子所占电极面积为0.62nm2,CLP在悬汞电极上的吸附符合Frumkin等温式.测得吸附系数β=6.28×105,吸引因素γ=0.75,电子转移数n为2,不可逆吸附的转移系数α为0.53.探讨了CLP在汞电极上的还原机理,并建立了吸附溶出伏安法测定CLP的最佳条件,检测限为8.0×10-9mol/L.  相似文献   

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